Hi All

Efficiency of PV cells is climbing all the time, especially for concentrator systems (space being one important app.) Here's a physorg news bite...

Spectrolab Latest Hits

...now reaching 40.7%, with theoretical limit of 58% not so far away.

Geoffrey Landis published a design for a concentrator system for an SPS which uses inflatables for the structure and mirrors. By themselves the collectors massed a mere 800 tons, with 35% efficiency PVs and 1 GW delivered to the ground @ 33% transmission efficiency - 1,300 tons total mass. For in-space power and 50% efficient cells the mass drops massively. Imagine supplying 300 MW for a Mag-Beam propulsion system - the array mass drops to a mere 91 tons instead of the thousands of tons of batteries quoted in the original design. A Mag-Beam launcher could conceivably be launched by a single HLLV.